package number;

public class Rand7Rand5
{

  public static int rand7()
  {
    while (true) {
      int num = 5 * rand5() + rand5();
      if (num < 21) {
        return num % 7;
      }
    }
  }

  public static int rand5()
  {
    return (int) (Math.random() * 100) % 5;
  }

  public static void main(String[] args)
  {
    /* Test: call rand7 many times and inspect the results. */
    int[] arr = new int[7];
    int test_size = 1000000;
    for (int k = 0 ; k < test_size ; k++) {
      arr[rand7()]++;
    }

    for (int i = 0 ; i < 7 ; i++) {
      double percent = 100.0 * arr[i] / test_size;
      System.out.println(i + " appeared " + percent + "% of the time.");
    }
  }

}
